City of Sudbury Water and Sewage Treatment Plants

The SolarWall® panels cover 185 m2 (2000 ft2 ) of the south wall. The heat is ducted from the top of the solar panels, along the roof, to two heat pump units. This provides 81kW of heat and ventilation air to the facility, which is very important because an adequate level of ventilation air is necessary to maintain the indoor air quality in the facility.

Sewage Treatment Plant

The solar heat from the 700 m2 (7500 ft2
)
SolarWall heater is used in two ways. One wall
section heats the ventilation air required in the
building. The other wall section preheats the air to
the blowers in the aeration tanks. In winter, ice
can build up on the compressor vanes causing
damage. By preheating the cold air, and potential
ice buildup is either eliminated or melted by solar
energy. The total airflow is 21,000 cfm, and the
heating capacity is 308kW.

Background

Like most cities, energy costs
represented the second highest municipal
expenditure for Sudbury, Ontario
exceeded only by labour. Given that
energy was such an enormous part of
their budget, the goal was to reduce
those costs by producing some of their
own energy using renewable sources.
Part of that included overhauling the
existing Wanapetei Water Treatment
Facility and Sewage Treatment Plant.
The planned work consisted of various
energy related retrofits, including
upgrades to process equipment,
building envelopes and HVAC systems.
Conserval Engineering was contacted
regarding a solar heating and ventilation
system that would optimize energy gain
and reduce heating costs.

Solution

Two words sum up Sudbury’s approach to managing their municipal facilities: energy efficiency. This job has garnered
the city a significant amount of media attention, as local newspapers, the Globe & Mail, and CBC News have
commended the municipality for their innovative approach to permanently and significantly reducing heating costs, and
lowering the use of polluting fuel sources.
As a result of the success of the first two projects, the City of Sudbury ended up specifying a third SolarWall system on
another municipal water treatment plant. In this application, the solar panels will heat re-circulated air.